In a large bowl, cream butter and sugar until light and fluffy. Beat in egg and molasses. Dissolve tea in water. Combine the flour, baking soda, ginger and salt; add to creamed mixture alternately with tea, mixing well after each addition. Stir in zest.
Pour into a greased 9-in. square baking pan. Bake at 350° for 30-35 minutes or until a toothpick inserted in the center comes out clean. Cool for 10 minutes before removing from pan to a wire rack to cool completely.
Just before serving, cut cake horizontally into two layers. Spoon peaches over bottom layer; replace top layer. Cut into individual servings; top with whipped cream.